HARMless: Transient Cortical and Sulcal Hyperintensity on Gadolinium-Enhanced FLAIR after Elective Endovascular Coiling of Intracranial Aneurysms

Abstract

Background and purpose: Cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR has been increasingly recognized after iodinated contrast medium exposure during angiographic procedures. The goal of this study was to assess the relationship of cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR against various variables in patients following elective endovascular treatment of intracranial aneurysms.

Materials and methods: We performed a retrospective review of 58 patients with 62 MR imaging studies performed within 72 hours following endovascular treatment of intracranial aneurysms. Patient demographics, aneurysm location, and vascular territory distribution of cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR were documented. Analysis of cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR with iodinated contrast medium volume, procedural duration, number of angiographic runs, and DWI lesions was performed.

Results: Cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR was found in 32/62 (51.61%) post-endovascular treatment MR imaging studies, with complete resolution of findings in all patients on the available follow-up studies (27/27). Angiographic iodinated contrast medium injection and arterial anatomy matched the vascular distribution of cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR. No significant association was found between cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR with iodinated contrast medium volume (P = .56 value) and the presence of DWI lesions (P = .68). However, a significant association was found with procedural time (P = .001) and the number of angiographic runs (P = .019). No adverse clinical outcomes were documented.

Conclusions: Cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR is a transient observation in the arterial territory exposed to iodinated contrast medium during endovascular treatment of intracranial aneurysms. Cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR is significantly associated with procedural time, and the frequency of angiographic runs suggesting a potential technical influence on the breakdown of the BBB, but no reported adverse clinical outcome or association with both iodinated contrast medium volume and DWI lesions was found. Recognition of cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR as a benign incidental finding is vital to avoid unnecessary investigation.

Fig 1.

Different patterns of cortical and sulcal hyperintensity on gadolinium-enhanced FLAIR in different patients. A and B, A 49-year-old woman with a postcoiling unruptured anterior communicating artery aneurysm via a right internal carotid artery approach. A, Postcoiling gadolinium-enhanced FLAIR shows CSHF along the right anterior cerebral artery territory (white arrows). B, Two-month follow-up Gd-FLAIR shows no residual abnormality. C and D, A 64-year-old woman postcoiling of a left paraclinoid ICA aneurysm via a left ICA approach. C, Postcoiling Gd-FLAIR shows CSHF along the left middle cerebral artery territory (white arrows) and left ACA territory (white arrowhead). D, Two-month follow-up Gd-FLAIR shows resolution of the abnormality. E and F, A 61-year-old woman with a postcoiling basilar tip artery aneurysm via a left vertebral artery approach. E, Postprocedural Gd-FLAIR shows CSHF along the left cerebellar fissures (white arrow). F, Two-month follow-up Gd-FLAIR shows no residual abnormality.

Fig 2.

A, Right internal carotid artery angiographic approach for coiling of a right ophthalmic ICA aneurysm (black arrowhead) in a 71-year-old woman using 7.78 mL/kg of iodinated contrast volume and a procedural time of 4 hours. Note the presence of fetal origin of the right posterior cerebral artery (black arrow). B, Gadolinium-enhanced FLAIR performed at 12 hours after endovascular coiling shows cortical and sulcal hyperintensity along the right middle cerebral artery territory (white arrows) and the right PCA territory (white arrowheads). C, Corresponding DWI shows no diffusion restriction. D, A follow-up unenhanced CT scan obtained on the same date shows no evidence of subarachnoid hemorrhage. E, Two-month follow-up Gd-FLAIR shows no residual abnormality.